Other

ICubeCorp - "Unified Processing Unit": a multi-processor multi-threaded architecture with hybrid instructions for general-purpose computing, 3D Graphics and Video processing all in the same architecture.

GeneralPlus GP3300 http://www.cnx-software.com/2012/06/11/generalplus-gp3300-cortex-a8-processor-and-android-tablet-reference-design/ This CPU is a 1ghz Cortex A8, has HDMI and LVDS as standard, but only has MII Ethernet on the BGA328 version, and only has one USB2 interface on both versions. The LQFP216 version only has a 16-bit DDR3 RAM interface that can only access up to 512mb of RAM, whereas the BGA328 version can do 32-bit DDR3 up to 1gb. Unfortunately, both versions with no SATA would require an additional $2.50 to $3.00 of support ICs in order to use them for an EOMA-CF or EOMA-68 CPU Card, making both versions of the GP3300 economically cost uncompetitive when compared to the Allwinner A10.

Marvell Armada 510 because it has SATA-II, but Marvell's NDA policy is generally prohibitive, Marvell themselves not too hot on the concept of "source code", pricing is impossible to obtain and their CPUs do not have interoperability with Cortex A8/9 instruction sets. decision not yet made. http://www.marvell.com/application-processors/armada-500

ST spear1340http://www.st.com/internet/mcu/product/251211.jsp - this is a superb CPU, dual-core cortex a9 600mhz, but it is 628-pins and so pricing is likely to be quite high. it does however include gigabit ethernet, SATA-II, PCI-e and 3x USB2. power consumption is surprisingly heavy, at over 2 watts (even though it is 600mhz).

Texas Instruments am389x 12.ghz ARM Cortex A8, which is noteworthy for its incredibly fast DDR3 1600mhz 64-bit-wide RAM interface, as well has having SATA-II, Gigabit Ethernet, PCIe 2.0, HDMI out and much more. The only downside is that it's a specialist IC with over 1,000 pins, so is quite costly compared to other options. It is however pin-compatible with some incredibly powerful other SoCs including the TMS320DM8168.

Rejected CPUs (for mass-volume purposes)

These CPUs are either too expensive, too power hungry, do not have enough features, or are sufficiently unavailable as to be not worth pursuing. Some of these CPUs would be suitable for FSF Hardware-Endorsement purposes (see separate section below) but for the purposes of mass-volume mass-market products they do not have the processing power required for "today's" modern devices.

However, for emerging markets, some of these devices may be suitable.

MIPS

The Ingenic jz4760 is a PRC-home-grown MIPS, 90nm, 700mhz. It is $USD 7 in mass-volume. It has X-Burst Vector Processing (8-stage pipeline with SIMD capability) but at only 700mhz it can only do 720p video, not 1080p video decode. Therefore, sadly, it had to be rejected on the grounds that it did not have sufficient features for mass-volume sales, despite the possibility of it being FSF Hardware-Endorseable.

The Ingenic jz4770 is the successor to the jz4760, 65nm, 1ghz. It is $USD 7.50 in mass-volume. Sadly, there is evidence which tends to suggest that X-Burst would not run correctly in 65nm (8-stage pipeline not being long enough). Ingenic placed two X-Burst units at 500mhz on-board, sufficient to provide 1080p video decode, but for 3D Graphics sadly they decided to license Vivante's GC600. This CPU, which would otherwise be perfect for FSF Hardware-Endorsement, is now competing based purely on price-performance with all other ARM-based SoCs. With no on-board HDMI and no on-board SATA-II, compared to other near-identical SoCs the jz4770 sadly isn't good enough.

ARM

The TI OMAP, AMxxxx and DMxxxx series of CPUs are, almost without exception, significantly overpriced or under-featured. the OMAP3530 can only do 720p video decode, for example, yet is $USD 45 in 1k volumes. Some of the TI CPUs go as high as 1,000 pins and $90, which is far too much. The smaller less-featured CPUs come in around $USD 5 in mass-volume, such as the AM335x series, but with no SATA-II the cost of adding SATA-II via USB (appx $3.50 in extra components) automatically makes it cost-uncompetitive.

The TI OMAP 44xx series of CPUs are EU and USA export-restricted, and only available in mass-volume quantities of 100k units and above. Pricing has not been determined. The only company in the world that is has a license to be supplied with TI OMAP 44xx CPUs in volumes less than 100k is selling modules with less RAM and for more money than Pandaboards, and their fees for creating new modules are charged at $150 per hour. Passing on such cost to Software (Libre) Developers as well as mass-volume end-users seems somewhat to defeat the exercise.

The Freescale IMX53 1GHz is an indeterminate price, estimated to be around $15, contains a proprietary 3D GPU, and is only a Cortex A8. It is therefore approximately half the price-performance metric of the best comparable SoCs. However, Freescale have a policy, like TI, of GPL compliance and releasing full board schematics, available here so it is still worthwhile considering.

The 800mhz AMLogic AML8723 is around $13 in mass-volume, contains a MALI 400MP GPU, and is a Cortex A9 (single-core). However, its memory is hard-restricted to 512mb. Also there are other factors which cannot be described here which also eliminate - with prejudice - this CPU and all CPUs from AMLogic, from RHT's consideration until further notice.

The 1ghz Samsung S5PV210 is around $19 in mass-volume, so on price-performance alone is uncompetitive. It is also only available in 10k volumes: Samsung has a policy of not speaking to "small" China-based Factories for small volume orders.

Telechips have been buggers to get hold of, and are forcing ODMs to sign an NDA, in direct violation of the GPL.

Various other obscure PRC-based ARM licensees have also come out the woodwork, but the price compared to the Allwinner is still $4 to $6 more, for approximately the same features, making them not worthwhile pursuing right now.

Ziilabs CPUs have also been rejected for GPL violations and for lack of open-ness regarding the on-board cell processor

x86

Then there are the following x86 options, all of which are eliminated on the basis of far too high cost, as well as being well over the power budget (5 watts peak, 3.5 watts nominal, for heat dissipation reasons).

The 1ghz RDC IAD100HV x86 clone. The power consumption is over 2 watts, and it has no on-board 3D Graphics. It does have a PCI-e interface. finding a low-cost, low-power PCI-e 3D GPU is impossible. They just don't exist. the lowest powered GPU on the market is from SIS and it's 8 watts. 6 if it is run at a lower power and clock speed. But, as it's an older 65nm fab process, that 6 watts is a permanent continuous usage. And there's no on-board memory so you now need 2 lots of DDR2 RAM: one for the CPU, and one for the GPU. Bottom line is: expect the power consumption to be around 10 watts - a whopping 200% more than the available budget.

The VIA NANO range. again: an x86 clone. The only CPU capable of running at 1 watt is the 500mhz single-core NANO. that's way too slow. The dual-core version has a power budget over 2 watts, even in 45nm. Add on the cost of the Northbridge IC and its power requirements, and you're over 6 watts.

The new Intel Atom Z510. The lowest-speed CPU is 2 watts TDP, with the Northbridge IC being 2.5 watts. Excluding DDR RAM, the power budget is already exceeded. Additional ICs would be needed to add in SATA-II, HDMI and even Ethernet. With the power and cost budget already exceeded, this CPU was quickly eliminated.

The AMD Geode LX900. This was the CPU that was used in the OLPC XO-1. Although, technically, this CPU is superb and, because of its amazing internal self-clocking design, it is within the power budget, it has no 3D Graphics; its MPEG decode (actually it's MMX instructions plus a YUV-to-RGB hardware accelerator) is only capable of about 480p @ 30fps. Overall it's just too old and too slow. Superb design, shame about the lack of committment from AMD after buying the design from National. Also, it's missing SATA-II and HDMI, which would have to be added on as external ICs, increasing the cost even more.

Overall it has been somewhat hell to find CPUs that meet the criteria, despite knowing that, with the introduction over 2 years ago of 1ghz Cortex A8 CPUs that the "Good Enough Computing" threshold had been passed for quite some time.

Sadly, none of these CPUs however fulfil the mass-volume criteria of being able to do 3D Graphics or 1080p video. Some of them can do 720p, but that is not enough for commercial mass-volume purposes: it really does have to be 1080p now. 4 years ago, 720p was acceptable: now it isn't.